Electronic controller apparatus

Abstract

An improved electronic control system employs a primary servomechanism loop which includes an error signalling difference node and a stability compensating forward gain/drive element intermediate an input command signal source and a controlled output element. A second, similar image feed back loop is operative upon a simulated representation of the controlled output element or plant, and is exercised by the input command source. The error node in the second image loop generates a loop error signal responsive to the difference between the input command and the simulated, predicted response for the controlled element. In accordance with the present invention, the two error signals produced by the actual and image feed back loops are compared and generate a supplementary feed back signal which is summed with the plant-driving signal applied to the controlled element. Accordingly, the structure above considered operates to vitiate any difference between the error signals in the actual and image loops, thereby forcing the response of the controlled element to track the desired, predicted response therefor in the image loop notwithstanding any degredation experienced by the controlled plant.

What is claimed is: 
     
       1. In combination in apparatus for controlling a controlled element; primary feed back loop means including feed back signal supplying means for supplying a signal representing the state of the controlled element, as an input signal source, first difference means having inputs connected to said input signal source and to said feed back signal supplying means for providing a primary loop error signal, and forward gain means responsive to said primary loop error signal generated by said first difference means for driving the controlled element; image feed back loop means including controlled element simulating means, second difference means having inputs connected to said input signal source and to an output of said simulating means for providing an image loop error signal, and second forward gain means connecting said second difference means and said simulating means; and third difference means, having inputs connected to said first and second difference means for augmenting the drive applied to the controlled element responsive to the difference between said error signals in said primary and image feed back loop means, wherein said third difference means includes integrating steady state means responsive to the error signal difference in said primary and image feed back loop means, and multiplier means for multiplying the output of said steady state means and said primary feed back loop error signal determined by said first difference means. 
     
     
       2. A combination as in claim 1, further comprising a controlled element connected to said forward gain means. 
     
     
       3. A combination as in claims 1 or 2 wherein said simulator means simulates the actual response of the controlled load. 
     
     
       4. A combination as in claims 1 or 2 wherein said simulator means simulates an ideal response of the controlled load. 
     
     
       5. A combination as in claims 1 or 2 further comprising change monitoring means connected to said third difference means.